Boko Haram pledges allegiance to IS
Nigeria's home-grown Boko Haram Islamic extremists have pledged formal allegiance to the Islamic State group.
The pledge came in a message allegedly by the Nigerian insurgent leader posted on Twitter and reported by the SITE Intelligence monitoring service.
The unverified pledge comes as the Nigerian militants are reportedly massing in a north-eastern town for a showdown with a multinational force that has dislodged them from a score of towns in recent weeks.
Boko Haram leader Abubakar Shekau made the oath in Arabic in a tweeted message, saying: "We announce our allegiance to the Caliph of the Muslims."
IS leader Abu Bakr al-Baghdadi has declared himself the caliph.
Police said four suicide bomb attacks hit the city of Maiduguri on Saturday, killing at least 54 people and wounding 143 in the heartland of Nigeria's north-eastern Islamic extremist uprising.
The blasts occurred over four hours in locations from a busy fish market to a crowded bus station, said police commissioner clement Adoda.
A fifth explosion from a car bomb at a military checkpoint 50 miles outside the city wounded a soldier and two members of a civilian self-defence unit.
The bomber apparently wanted to reach Maiduguri, said a police officer at the scene who spoke on condition of anonymity because he is not allowed to speak to the press.
In the deadliest blast, 18 people died when a suicide bomber blew himself up in a tricycle taxi at the entrance to the bustling Baga fish market, police said.
"I saw many dead bodies lying on the ground, many dead, and several others badly injured," said fish seller Idi Idrisa.
The Boko Haram pledge to IS comes as the Nigerian militants reportedly are massing in the north-eastern town of Gwoza, considered their headquarters, for a showdown with a Chadian-led multinational force.
Though there was no way to independently verify the message, it comes weeks after Boko Haram's new Twitter account broadcast that the group's Shura council was considering whether to swear formal allegiance to IS.
The Twitter account, increasingly slick and more frequent video messages from Boko Haram, and a new media arm all are considered signs that the group is being helped by IS propagandists.
Boko Haram in August followed the lead of IS in declaring an Islamic caliphate in north-east Nigeria that grew to cover an area the size of Belgium.
Islamic State has declared a caliphate in vast swathes of territory that it controls in Iraq and Syria.
The Nigerian group also began publishing videos of beheadings. The latest one, published March 2, borrowed certain elements from IS productions, such as the sound of a beating heart and heavy breathing immediately before the execution, according to SITE.
In earlier video messages last year, Shekau sent greetings and praise to both al-Baghdadi and leaders of al-Qaida.
But some analysts surmise Boko Haram has never been an affiliate of al-Qaida, because al-Qaida considers the Nigerians' indiscriminate slaughter of Muslim civilians as un-Islamic.